This invention relates to an optical recording apparatus in which a recordable optical disc is used as the recording medium. More particularly, it relates to an optical disc recording apparatus which is provided with decision means for deciding if the optical disc attached to the optical disc recording apparatus is a pre-recorded optical disc, that is a disk on which information signals have been recorded, or an unrecorded disc.
In the field of recording of information signals, a variety of disc-shaped recording media, such as optical discs or magneto-optical discs, utilizing optical or magneto-optical signal recording/reproducing methods, have been developed and presented to the market. These disc-shaped recording media include read-only-memory (ROM) type recording media, such as compact discs (CDs), write-once type recording media, or which data writing may be made only once by the user, and overwrite type recording media, on which data overwriting may be made, such as magneto-optical discs.
With an optical disc recording/reproducing apparatus for writing or reading out data on or from an optical disc, such as the aforementioned write-once type disc or the overwrite type disc, the rotational speed of a spindle of a disc driving device adapted for rotating the optical disc is controlled for rotating the optical disc at a constant angular velocity or at a constant linear velocity. The optical disc rotated by the disc driving device is irradiated with a laser light from a semiconductor laser enclosed within the optical head, while the return laser light irradiated on and reflected back from the optical disc is detected by a photodetector enclosed within the optical head for recording/reproducing the information on or from the optical disc.
On the other hand, in order that the laser light radiated from the semiconductor laser may be correctly converged on the signal recording surface of the disc and be able to follow the recording track formed on the optical disc in the correct manner, the optical head also performs focusing control and tracking control for the laser light on the basis of the detection output obtained upon detection of the return laser light from the optical disc by the photodetector.
In the case of an optical disc recording apparatus in which the write-once type optical disc is used as the recording medium, if a pre-recorded optical disc is inadvertently attached to the optical disc recording apparatus for recording information signals thereon, without ascertaining in advance if the disc is an unrecorded disc or a pre-recorded disc, the result is that information signals are overwritten on and destroy the pre-recorded information signals.